How do I test these?

[Bino]

many, many, many moons ago I acquired 4 of these colour light signals. They are all Green/Red and as can be seen, 2 wires are attached to each light.

 

They are of no use to me but, before I stick them on Ebay, I'd like to test them. Trouble is, I've no idea how to. Can anyone suggest how they should be wired?

Edited March 3, 2023 by Bino
Forgot to add the pic!

[john new]

Photo?

 

[Bino]

6 minutes ago, john new said:

Photo?

 

sorry, added now

[PJ10]

Hi. A slightly better picture of the signal head may be required but they appear to be bulbs as opposed to LEDs. And this would be the case if they are very old as you suggest. The green wires appear to be for the green bulb so I guess the red wires are for the red bulb. I'd wire each pair of wires separately to my DC controller track output and slowly turn the control dial. I would expect the bulb connected to begin to glow when the dial is turned. Be careful not to turn the dial too far as you will blow the bulb.

 

PJ10

 

 

[kevinlms]

4 minutes ago, PJ10 said:

Hi. A slightly better picture of the signal head may be required but they appear to be bulbs as opposed to LEDs. And this would be the case if they are very old as you suggest. The green wires appear to be for the green bulb so I guess the red wires are for the red bulb. I'd wire each pair of wires separately to my DC controller track output and slowly turn the control dial. I would expect the bulb connected to begin to glow when the dial is turned. Be careful not to turn the dial too far as you will blow the bulb.

 

PJ10

 

 

Don't do that with a resistance mat controller, as often these put out around 20 Volts on no/small loads.

[smokebox]

9volt pp3 battery may be the safest?

[PJ10]

14 minutes ago, kevinlms said:

Don't do that with a resistance mat controller, as often these put out around 20 Volts on no/small loads.

Agreed. I forgot some people still use these.

[MartinRS]

I can't tell if they are grain of wheat bulbs or LEDs. I would use a multimetre set to the oms range and test them with a (say) 100 ohm resistor in series, then reverse the polarity of the mulimetre leads. if they conduct in both directions then you have bulbs. If they only conduct in one directions then you have LEDs. Applying more than a couple of volts to a  LED could damage it. 

[Bino]

[AY Mod]

[rogerzilla]

They must be grain of wheat bulbs as the current direction, based on wire colour, doesn't matter.

 

2-aspect LEDs would have a red (yellow if a distant signal), green and (normally black) common wire.

[Bino]

Thanks for the responses. 

 

I've connected them briefly to a 9v battery and all but one bulb lights up.

 

If I was to keep them, how would I wire the switch? What resistor would I need if using a 16v AC supply and where would it be placed in the circuit?.

[john new]

19 minutes ago, Bino said:

Thanks for the responses. 

 

I've connected them briefly to a 9v battery and all but one bulb lights up.

 

If I was to keep them, how would I wire the switch? What resistor would I need if using a 16v AC supply and where would it be placed in the circuit?.

On the old Hornby Dublo equivalent (Those look like a Merit product but I might be wrong) they need a permanent contact on-off switch and are 12V DC bulbs (I ran mine though with a lower voltage). For the two colours you need a double pole switch - three connectors centre feed and the either or output lines.  Old hat but the old Hornby Dublo switches were individually fed so you could mount the DC on-off switches (feeding the colour light signal bulbs) and AC passing contact switches (point/semaphore signals) side by side with the relevant levers linked by a bar. Switch one switch both. Not sure you can with the modern Hornby type as they have the brass rod connector which I guess has the power feed in line. AC passing & DC permanent current don't mix!

 

I am sure someone will know of the modern way to do it.

 

Edited March 3, 2023 by john new
Reaised I'd missed a bit out!

[Brian]

Hi

I'm assuming the lamps are 12volt rated as they tested on a PP3 9volt battery OK.

You need an On/On switch or lever.   SPDT toggle switch, Hornby R046 yellow lever. Peco PL-23 etc

 

At the signal connect together one green and one red wire (doesn't matter which one of the two) and take that to the negative of a 9 to12 volt DC power supply - A DC regulated power supply would be best IMO rather than a train controllers output or 16v AC.   To Note, a series resistor if one is used would be in the supply to the switch or alternatively the return wire from the signal. It will get hot and you would need to calculate the actual resistance and wattage needed!  Hence my recommendation to use a 9 to 12v regulated Power source and then no series resistance is then needed. 

 

The switch or lever will have three connections. The common connection connects to the positive of the supply. The remaining two connections each go to the red and the green wires of the signal.   On a toggle switch the common is the middle of the three tabs. On the R044 the common is the lower middle socket and the Peco PL-23 the common is the middle tab.

Then when the switch or lever is in one position the red aspect is lit and move the switch or lever to the opposite position the green aspect will be lit.

Edited March 6, 2023 by Brian
Drawing added